Big pipe triggers big science on O.C. coast

Scientists George Robertson, left, and Michael Mengel, with the Orange County Sanitation District, deploy one of three new trawl-resistant bottom mounts loaded with current meters called Acoustic Doppler Current Profilers about 4.5 miles off the Orange County coast near Newport Beach earlier this month. The tools are designed to measure ocean currents and are being deployed by crews at depths of between 40 and 60 meters. JOSHUA SUDOCK, THE ORANGE COUNTY REGISTER

The repair of a massive pipe that carries wastewater to the ocean is inspiring one of the most elaborate scientific investigations in years along the Orange County coast.

Missile-shaped robotic gliders, sensors tethered offshore and boats crisscrossing the ocean with instruments in tow – all are part of an attempt to learn which life forms might be stimulated by a sudden burst of treated effluent closer to shore than usual. Even satellite readings, courtesy of the Jet Propulsion Laboratory in Pasadena, will help characterize the footprint of the effluent "plume."

"We're measuring where the plume is, trying to find the plume and predict where it's going, based on measurements of currents and meteorological data," said Jim Herberg, assistant general manager and director of engineering at the Orange County Sanitation District.

The main effluent pipe extends 41/2 miles out to sea from Huntington Beach and is 10 feet in diameter from beneath the sand all the way to the diffusers at the far end, where the effluent is released at a depth of 200 feet.

The beach side of the pipe, in operation since the 1970s, will be fitted with a new, stainless-steel liner; other corroded parts must be replaced.

In a project that began this month and will continue into October, the effluent is being channeled through a shorter, secondary pipe, extending only a mile offshore and releasing effluent at a depth of only 60 feet. That is giving the scientists an opportunity: measure the effect of effluent on the growth of different forms of algae to see which might bloom under its influence.

Blooms of algae and other life forms are fed by nutrients such as nitrogen and phosphorous, welling up from deeper water after storms and, perhaps, flowing from land; whether effluent discharges, which include such nutrients, help stimulate the blooms is unknown.

But some blooms can cause serious problems along the coast.

Tiny creatures that are part of an algae group known as diatoms can release a toxin, domoic acid, that can damage the brains of larger animals, such as sea lions and pelicans; serious domoic acid outbreaks sometimes cause sea mammals or birds to exhibit strange symptoms before dying.

Scientists are trying to learn which nutrients stimulate which kinds of blooms, and under what conditions. Although environmental conditions that give rise to blooms are generally understood, scientists do not know which conditions give rise to harmful blooms.

"There's no reason to assume that harmful algae dominate the system, and every reason to monitor it," said University of Southern California researcher Dave Caron.

Caron is part of a research group trying to understand how algae respond to infusions of nutrients off the Southern and central California coasts.

And the Sanitation District effluent is chocked with nutrients such as nitrogen and phosphorus, prompting strong interest for his scientific team and others.

But because the effluent carries virtually no bacteria, it is not expected to pose a human health threat.

The effluent is disinfected with bleach before leaving the Sanitation District's treatment plant, then stripped of bleach before being piped out to sea.

And that comes after multiple levels of treatment to remove other contaminants.

So Sanitation District officials say they expect no noticeable effects on water along the shore, or on swimmers and beachgoers.

Still, the effluent will be released far closer to shore, and at a shallower depth, where it can potentially nourish different forms of algae. Because the longer pipe releases the wastewater at a depth of 200 feet, and is then diluted, it would be expected to provide little nourishment to algae and other life forms near the surface.

Those deep-water releases are well below the "lighted zone" in the water column, the realm of a variety of tiny organisms known collectively as phytoplankton because they, like land plants, rely on photosynthesis, combining sunlight and carbon dioxide to make energy.

That's why the scientists are eagerly anticipating the potential effects of releases at a shallower depth.

"For 20 to 35 days, the discharge will be right at the surface, where the phytoplankton are, potentially stimulating a phytoplankton bloom," said George Robertson, a senior scientist at the Sanitation District.

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Scientists George Robertson, left, and Michael Mengel, with the Orange County Sanitation District, deploy one of three new trawl-resistant bottom mounts loaded with current meters called Acoustic Doppler Current Profilers about 4.5 miles off the Orange County coast near Newport Beach earlier this month. The tools are designed to measure ocean currents and are being deployed by crews at depths of between 40 and 60 meters. JOSHUA SUDOCK, THE ORANGE COUNTY REGISTER
Senior environmental specialists Hai Nguyen, left, and Laura Terriquez use an acoustic tracking system to verify the position and orientation of newly deployed trawl-resistant bottom mounts loaded with current meters called Acoustic Doppler Current Profilers about 4.5 miles off the Orange County coast near Newport Beach earlier this month. Sitting level against the sea floor is important for gathering the most accurate data. JOSHUA SUDOCK, THE ORANGE COUNTY REGISTER
Scientists from the Orange County Sanitation District deploy one of three new trawl-resistant bottom mounts loaded with current meters called Acoustic Doppler Current Profilers earlier this month. The tools are designed to measure ocean currents and are deployed at depths of between 40 and 60 meters off the Orange County coast. JOSHUA SUDOCK, THE ORANGE COUNTY REGISTER
Senior environmental specialist Hai Nguyen preps a current metering device called an Acoustic Doppler Current Profiler to be installed aboard one of three new trawl-resistant bottom mounts that will monitor ocean currents off the Orange County coast earlier this month. JOSHUA SUDOCK, THE ORANGE COUNTY REGISTER
Captain Tom Pesich, left, and senior environmental specialists Ken Sakamoto and Laura Terriquez assist as other crew members deploy three new trawl-resistant bottom mounts loaded with current meters called Acoustic Doppler Current Profilers about 4.5 miles off the Orange County coast near Newport Beach earlier this month. The tools are designed to measure ocean currents and are being deployed by crews at depths of between 40 and 60 meters. JOSHUA SUDOCK, THE ORANGE COUNTY REGISTER
The telecommunications portion of a submerged Orange County Sanitation District environmental sensing platform protrudes from the ocean off the coast of Newport Beach. The submerged device, resting on the ocean's floor and tethered to the telecommunications buoy, measures algae and bacteria levels. The telecommunications buoy transmits that data back to scientists at land-based research centers. JOSHUA SUDOCK, THE ORANGE COUNTY REGISTER
Scientists George Robertson, left, and Michael Mengel, with the Orange County Sanitation District, deploy one of three new trawl-resistant bottom mounts loaded with current meters called Acoustic Doppler Current Profilers about 4.5 miles off the Orange County coast near Newport Beach earlier this month. The tools are designed to measure ocean currents and are being deployed by crews at depths of between 40 and 60 meters. JOSHUA SUDOCK, THE ORANGE COUNTY REGISTER
A dolphin trails behind an Orange County Sanitation District research vessel off the coast of Newport Beach earlier this month. The crew checked in on old and deployed new ocean monitoring equipment. JOSHUA SUDOCK, THE ORANGE COUNTY REGISTER
Scientist George Robertson applies a coat of Vaseline mixed with generic chili powder over the four lenses of a current metering device called an Acoustic Doppler Current Profiler. He says this prevents things like barnacles from attaching to the sensitive equipment, which could impact their measurements. JOSHUA SUDOCK, THE ORANGE COUNTY REGISTER
Scientist George Robertson prepares to load a current metering device called an Acoustic Doppler Current Profiler onto a rig known as a trawl-resistant bottom mount. The The tool is designed to measure ocean currents and are being deployed at depths of between 40 and 60 meters off the Orange County coast by researchers with the Orange County Sanitation District. JOSHUA SUDOCK, THE ORANGE COUNTY REGISTER
Project Manager Pam Koester of the OC Sanitation District, stands in a stainless steel insert that will be used to repair a pipe that transports treated sewage about five miles out into the ocean. While the repairs are taking place, another pipe will transport waste about a mile into the ocean. EUGENE GARCIA, THE ORANGE COUNTY REGISTER
Construction engineering supervisor Chris Cervellone of the OC Sanitation District, surveys equipment in a temporary sampling facility, as part of a project to repair a pipe that transports treated sewage nearly five miles out into the ocean. EUGENE GARCIA, THE ORANGE COUNTY REGISTER
OC Sanitation District workers stand near a stainless steel insert, left, that will be used to repair a pipe that transports treated sewage nearly five miles out into the ocean. The insert will be lowered into the surge tower on the right and manuevered into place in a 'beach box.' EUGENE GARCIA, THE ORANGE COUNTY REGISTER
Workers ready a corroded 'beach box,' where a new stainless steel insert will be used to repair a pipe that transports treated sewage nearly five miles out into the ocean. While the repairs are taking place, another pipe will transport waste about a mile into the ocean. bigpip2.0912 9/10/12 Photo by Eugene Garcia, The Orange County Register EUGENE GARCIA, THE ORANGE COUNTY REGISTER
Clamps hold an adjustable stainless steel insert at a 116-inch diameter that will later be expanded to 120 inches to fit into a pipe that transports treated sewage nearly five miles out into the ocean. EUGENE GARCIA, THE ORANGE COUNTY REGISTER
OC Sanitation District workers walk along a temporary path used to access repairs on a pipe that transports treated sewage nearly five miles out into the ocean. The project aims to create minimal impact to the community and wildlife, by putting up orange fences to protect wildlife and sound barriers to minimize construction noise. EUGENE GARCIA, THE ORANGE COUNTY REGISTER

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